Iron is needed for the formation of haemoglobin in red blood cells, which transports oxygen around the body. Iron is also required in myoglobin in the muscle cells and also in many cell enzymes.
Iron needs are greatest in women of child-bearing age, as iron lost through menstruation must be replaced.
Iron absorption
The main factor controlling absorption is the amount of iron stores in the body. Iron absorption is also controlled by the requirements of a particular individual and the amount of iron consumed. The presence of particular components in foods can enhance or inhibit the absorption of iron.
Iron sources
There are two types of iron sources. Haem iron is from meat, poultry and fish and is typically well absorbed. Non-haem iron is found primarily in plant based foods, iron supplements and is the type of iron used for fortification of foods, e.g. cereals. Non-haem iron is not as well absorbed
Combining non-haem iron with meats and good sources of Vitamin C improves the absorption of non-haem iron. Components which inhibit the absorption of non-haem iron are polyphenols (in tea, coffee, and particular vegetables) and phytates (in unrefined cereals, nuts and legumes.) These components bind to the iron making it harder, or impossible, for the iron to be processed and absorbed and make it unavailable for use in the body.
RDI for Iron (mg/day for NZ)
Men 19-54+ years = 7mg/day
Women 19-54 years = 12-16mg/day
Women 54+ years = 5-7mg/day
The most recent National Nutrition Survey indicated that low iron stores and iron-deficiency anaemia mainly affected women. Females aged 15–18 years had a prevalence of inadequate intake of 34.2%; those aged 31–50 years had a prevalence of 15.4%.
Iron deficiency
A lack of iron in the diet, leads to low iron stores in the body and eventually to iron-deficiency anaemia. As so much of the body’s iron is in the blood, losses are greatest whenever blood is lost. Symptoms of iron deficiency are usually a lack of energy, reduced resistance to colds and inability to concentrate. Either iron supplements or changing food choices may be required to increase iron stores and cure iron-deficiency anaemia. The use of supplements should be discussed with a health professional.
Food sources of iron
To maintain iron stores, eat plenty of iron-rich foods such as red meat, liver, fish and chicken, or if vegetarian eat plenty of iron rich plant sources, such as beans and lentils. Breakfast cereals and vegetables are important sources of iron in the New Zealand diet. To optimise iron intake, include foods rich in Vitamin C. Avoid tea and coffee at mealtimes as components of these drinks bind to iron and prevent the absorption of iron into the body.
Bread & Iron
The Bread group provided 12% of dietary iron for New Zealanders. Older males and females (71+ years) obtained more iron from Bread than males aged 15–18 years and all younger females.